Best known for his landmark Spiral Jetty (1970) - a 1,500-foot sculpture of mud, salt crystals, and rock coiling over ten acres of the Great Salt Lake, Utah - Smithson was one of a number of 1960s "Earthwork" artists who, fascinated by process and gesture, installed their works in ravaged industrial sites and far-flung corners of the world, creating pieces that were anti-monumental, deliberately ephemeral, and largely dependent upon photography as witness to their existence. In 1969 Smithson began a photographic series entitled "Mirror Displacements." During his travels to places like the Yucatan or the British Isles, he would unfurl an accordion-style set of folding mirrors along with his camera, embedding them in the ground so that the surrounding landscape was refracted in their snakelike forms. In February 1969 the artist prepared for the first of these pho-tographing trips by staging his project in miniature, creating groups of one-inch-square mirrors stuck in snow drifts on the roof of his Greenwich Street apartment building.